The invention relates to electronic prepress and imagesetting systems. More particularly, the invention relates to a system and method managing output in an electronic prepress environment.
Printing presses use plates to print ink onto paper and other media. One method used for creating plates has been to expose photosensitive film with the matter to be printed. When the film is developed, the matter imaged on the film is imaged onto a photosensitive plate, sometimes referred to as xe2x80x9cburningxe2x80x9d a plate. After processing, the plate can be used to print the matter onto a medium. A printing project is referred to as a job. A job can include one or more sheets, where a sheet is the media to be printed on. A sheet can be printed on one or two sides.
In a black and white printing job, there is usually one plate that is used to print black ink. In a color printing job, a different plate is used for each color ink. Typically, a color job will use three colors of ink: cyan, magenta, and yellow. This is because a combination of cyan, magenta, and yellow can be used to make other colors. Often, in addition to cyan, magenta, and yellow, black ink is also used. An additional plate is then required to print the black ink. Occasionally, one or more colors will be printed separately as well, referred to as a xe2x80x9cspot color.xe2x80x9d That color will also have its own plate.
To print on a press using a plate, the plate is installed on a press. The plate is generally held in place on the press by pair of clamps at opposite sides of the plate, referred to as a head clamp and a tail clamp. The plate is exposed to the appropriate color ink, and the inked plate is placed in contact with the media, such as a paper sheet, that is to be printed. Each image that is printed has a gripper edge. The gripper edge is the edge of a sheet (i.e. printed media) that is pulled through the press. A gripper edge marker is often explicitly included in an image as part of a job at the front end, for example with imposition software, such that the gripper edge marker is visible on the imaged plate. The gripper edge of a plate, which is the edge with the gripper edge marker, is attached to the press with the head clamp. By explicitly imaging the gripper edge marker onto the plate, the front end software ensures that there is sufficient distance between the head clamp and the image content so that the image on the plate can be printed.
Electronic prepress systems have used an imagesetter to receive raster data for imaging onto photosensitive film. The film is then used to create a plate. The imagesetter exposes the photosensitive film pixel by pixel, for instance, by scanning a laser across and down a piece of film. Generally, the laser is scanned more quickly across the film in one direction, referred to as the fast scan direction, and then is moved more slowly down the film, referred to as the slow scan direction. Electronics controls the laser to expose, or refrain from exposing, each pixel in the raster data in a precise and repeatable manner. Recently, platesetters also have been used to create plates directly from raster data without the use of film. Imagesetters, platesetters and other output devices for printing are also referred to generally as print engines or writing engines.
Print engines typically have been served by a dedicated raster image processor (RIP) connected between the print engine and a xe2x80x9cfront endxe2x80x9d computer running imaging application software such as Quark Express(trademark) offered by Quark, Inc. of Denver, Colo. and Adobe Pagemaker(trademark) by Adobe Systems Inc. of Mountain View, Calif. Exemplary front end computers run on operating systems such as Windows NT(trademark), MacOS(trademark) and UNIX(trademark). In a typical configuration, a Macintosh(trademark) front end is connected to a RIP which is coupled with an imagesetter. The RIP interprets the graphic information transmitted to it by the front end computer, and converts the graphic information into raster data that can be imaged by the print engine. The raster data produced by the RIP is configured to match required parameters of both the imagesetter and the media. The imagesetter parameters include imaging resolution, processing speed and specific printing capabilities. The media parameters include the length, width and thickness of the media, as well as the chemical makeup of the photosensitive layer.
Typically, the imaging application software provides output in the format of a page description language (PDL) such as Postscript(trademark) and PDF(trademark) offered by Adobe Systems of Mountain View, Calif. Page description languages describe images using descriptions of the objects contained in the page. Use of page description languages allows pages to be described in a way that can be interpreted appropriately for imaging at various sizes and resolutions. PDL code is generally significantly smaller in data size than the raster data that results from interpreting the PDL code. Use of a page description language therefore allows for faster file transfer. Also, page description languages are machine-independent so that any print engine or other device which understands the PDL can produce an image therefrom.
When PDL image data is received by the RIP, operations performed by the RIP, such as using fonts to lay out text and color processing to create raster data for each color, typically results in one or more raster data bit maps. The raster data produced by the RIP is binary, meaning that each pixel is either on or off. The raster data for each of the colors in a color image is referred to as a color separation. A separation describes a single color plane, such as cyan, magenta, yellow, black, or a spot color.
Each color separation is transferred from the RIP to the output device over a high speed interface. This has historically been a parallel data transfer interface that provides a data transfer rate sufficient to keep the output device operating at a desired operating speed. Typically, the process of RIP processing data to prepare bit map image files for transfer to the output device has been slower than the imaging speed of the output devices. The slower RIP processing speed sometimes causes the output device to remain idle while waiting for a RIP to prepare the next bit map image file. The print engine is generally an expensive capital investment, so full time utilization of the print engine is desirable. Keeping the print engine busy is therefore a goal of modern electronic prepress system design.
The use of a RIP multiplexer (MUX), for example the MULTISTAR(copyright) offered by Agfa Corporation of Wilmington, Mass., offers the electronic prepress industry some improvement in data throughput, and associated cost savings, by functioning as a data buffer between one or more RIPs and a print engine. Cost savings and improved efficiency have been realized by either RIP processing an image with a first RIP while transferring a previously RIP processed image to the output device or by storing RIP processed raster data for transfer to the output device at an appropriate time after RIP processing. This multiplexer more fully utilizes the output device, and therefore provides increased throughput.
Typically, for prior art electronic prepress systems, a specific output device configuration had to be connected to the RIP before a job could be processed. For example, a print job requiring that a particular type of imagesetter be used for an output device, or that a particular media type or size be loaded onto the output device, could not be RIP processed into raster data if the particular output device connected to the RIP did not meet the job requirements. Improper output device configuration caused delay or, more frequently, required that a user take some action to physically change the output device connected to the RIP in order to continue processing and outputting image files. Since the electronic and imagesetting systems of the prior art were not only device dependent but media dependent as well, the queuing of rasterized print jobs for different media or output devices was not possible. Thus, the choice of the output device and print media proved to be a considerable hindrance in productivity.
RIP processing speed has improved so that the RIP is no longer a bottleneck in the pre-press workflow of single page printing jobs. As RIP processing speed has increased, however, so has the demands of output devices. Recent use of larger format imagesetters and platesetters allows multi-page press size images in film or plate, referred to as xe2x80x9cflats,xe2x80x9d to be produced that contain four, eight, or more pages in each image that are printed on one sheet of paper. These output devices also have been driven by a dedicated RIP or MUX. Because multi-page flats are complex, the RIP is often a bottleneck in creating these multi-page press format films and plates. The PDL code that must be interpreted to image multiple page flats is very complex. RIP processing time for complex images can require several multiples of the imaging time.
The invention relates to an output manager, also referred to as a print drive, which is between one or more raster image processors and one or more output devices in the prepress workflow. The output manager receives, stores, and transmits raster data of an image processed by the RIP. In one embodiment, the output manager manages both a high resolution image that is to be transmitted to an output device, and a related low resolution image that is made available to a press. The press uses the low resolution image to adjust the ink key settings and other image-related parameters.
In general, in one aspect, the invention relates to a method for including a reduced resolution continuous tone image in a print production format file. The method includes defining an output device, defining a press, and configuring a press profile in response to the output device and the press. The method also includes receiving a reduced resolution image, modifying the reduced resolution image responsive to the press profile, and storing the modified reduced resolution image in a print production file. In one embodiment, the print production file follows the CIP3 print production file format.
In one embodiment, the modifying step comprises converting the reduced resolution image to another resolution responsive to the press profile. In another embodiment, the modifying step comprises encoding the reduced resolution image responsive to the press profile. In another embodiment, the modifying step includes compressing the reduced resolution image responsive to the press profile. In another embodiment, the receiving step comprises receiving by an output manager a high resolution image and a reduced resolution image. In another embodiment, the method further includes providing the stored print production file to a CIP3 consumer application. In another embodiment, the press profile has a press profile name, an orientation, a resolution, file name information, a compression setting, an encoding setting, and a print production file format. In another embodiment, the press profile also includes job name and identifier information. In another embodiment, the press profile is received once for each imagesetter/press combination. In another embodiment, the high resolution image and the reduced resolution image are generated by a raster image processor while the image is processed by the raster image processor.
In general, in another aspect, the invention relates to a system for including a reduced resolution continuous tone image in a print production format file. The system includes an input for configuring a press profile, a receiver for receiving a reduced resolution image, a processor for modifying the reduced resolution image responsive to the press profile, and a data store for storing the modified reduced resolution image in a print production file according to CIP3 format. In one embodiment, the input is also used to associate the press profile with a job. In another embodiment, the processor includes a converter for converting the reduced resolution image to another resolution responsive to the press profile. In another embodiment, the processor includes an encoder for encoding the reduced resolution image responsive to the press profile. In another embodiment, the processor includes a compressor for compressing the reduced resolution image responsive to the press profile. In another embodiment, the system is an output manager. In another embodiment, the system includes a transmitter for providing the print production file to a CIP3 consumer application. In another embodiment the press profile has a press profile name, an orientation, a resolution, file naming information, a compression setting, an encoding setting, and a print production file format. In another embodiment, the press profile also includes job name and identifier information. In another embodiment, the input receives the press profile once for each imagesetter/press combination. In another embodiment, the high resolution image and the reduced resolution image are generated by a raster image processor when the image is processed by the raster image processor.
In another aspect, a system includes a memory storing a press profile, the press profile includes a file location, and orientation, a resolution, file name information, a compression type, and encoding type, and a print production file format. In one embodiment, the press profile includes one or more of the following parameters: a bend position, a second side configuration, an image byte alignment, and job name and identifier information.
The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description, figures and claims.